U.S. patent number 5,831,656 [Application Number 08/604,544] was granted by the patent office on 1998-11-03 for compact recording apparatus with efficient space utilization.
This patent grant is currently assigned to Canon Kabushiki Kaisha. Invention is credited to Takashi Chosa.
United States Patent |
5,831,656 |
Chosa |
November 3, 1998 |
**Please see images for:
( Certificate of Correction ) ** |
Compact recording apparatus with efficient space utilization
Abstract
A recording apparatus is provided with a carriage that causes a
recording head for recording on a recording medium to relatively
travel with respect to the recording medium, a mechanism unit for
driving the carriage and carrying the recording medium
simultaneously, and a power-supply circuit. This recording
apparatus includes a slanting portion arranged for the mechanism
unit as a passage for carrying the recording medium, and, in a
space made available below the slanting portion, the components
constituting the power-supply circuit are arranged substantially in
line in the direction substantially transverse to the slanting
portion of the mechanism unit. With the arrangement of such
structure, the efficiency of space utilization is enhanced and the
apparatus can be fabricated more compactly, thus attaining the
intended miniaturization thereof.
Inventors: |
Chosa; Takashi (Tokyo,
JP) |
Assignee: |
Canon Kabushiki Kaisha (Tokyo,
JP)
|
Family
ID: |
12326414 |
Appl.
No.: |
08/604,544 |
Filed: |
February 21, 1996 |
Foreign Application Priority Data
|
|
|
|
|
Feb 21, 1995 [JP] |
|
|
7-031261 |
|
Current U.S.
Class: |
347/108; 361/777;
174/261 |
Current CPC
Class: |
B41J
29/02 (20130101) |
Current International
Class: |
B41J
29/02 (20060101); B41J 029/13 (); H05K 007/02 ();
H01R 009/09 () |
Field of
Search: |
;347/12,13,209,210,108,109 ;358/296,400,502,503,300
;361/683,775,777,780,794 ;174/261 ;D18/55,56 ;400/88 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Le; N.
Assistant Examiner: Anderson; L.
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper &
Scinto
Claims
What is claimed is:
1. A recording apparatus provided with a carriage that enables a
recording head for recording on a recording medium to relatively
travel with respect to the recording medium, a mechanism unit for
driving said carriage and carrying said recording medium, and a
power-supply circuit having components for supplying power to said
recording head and said mechanism unit, said apparatus
comprising:
a slanting portion arranged for said mechanism unit as a passage
for carrying the recording medium, and in a space below said
slanting portion, the components constituting said power-supply
circuit being arranged substantially in line in a direction
substantially transverse to said slanting portion.
2. A recording apparatus according to claim 1, wherein said
power-supply circuit is formed on a printed circuit board, and a
width of a wiring pattern between the components constituting said
power-supply circuit is defined at a rate of 700 .mu.m or more per
current of 1 A passing through said wiring pattern.
3. A recording apparatus according to claim 1, wherein power-supply
circuit is formed on a printed circuit board, and a width of a
wiring pattern between the components constituting said
power-supply circuit is defined at a rate of 850 .mu.m or more per
current of 1 A passing through said wiring pattern.
4. A recording apparatus according to claim 1, wherein said
power-supply circuit is formed on a printed circuit board, and a
width of a wiring pattern between the components constituting said
power-supply circuit is defined at a rate of 1 mm or more per
current of 1 A passing through said wiring pattern.
5. A recording apparatus provided with a carriage that enables a
recording head for recording on a recording medium to relatively
travel with respect to the recording medium, a mechanism unit for
driving said carriage and carrying the recording medium, and a
controller having a base board including a power-supply circuit,
components constituting said power-supply circuit being arranged on
one face of said base board, and being connected with each other by
wiring patterns, said apparatus comprising:
a slanting portion arranged for said mechanism unit as a passage
for carrying the recording medium, at least a part of said base
board being arranged in a space below said slanting portion,
wherein said components constituting said power-supply circuit are
arranged substantially in line in a direction facing said space and
substantially transverse to a slanting direction of said slanting
portion, and a width of the wiring pattern between said components
constituting said power-supply circuit is defined at a rate of 700
.mu.m or more per current of 1 A passing through said wiring
pattern.
6. A recording apparatus according to claim 5, wherein the width of
said wiring pattern between said components constituting said
power-supply circuit is defined at a rate of 850 .mu.m or more per
current of 1 A passing through said wiring pattern.
7. A recording apparatus according to claim 6, wherein the width of
said wiring pattern between said components constituting said
power-supply circuit is defined at a rate of 1 mm or more per
current of 1 A passing through said wiring pattern.
8. A recording apparatus according to any one of claims 5 to 7,
wherein a one-chip central processing unit chip is arranged
substantially in the central portion of said base board.
9. A recording apparatus according to any one of claims 1 to 7,
wherein said recording head is an ink jet recording head for
discharging ink in accordance with signals.
10. A recording apparatus according to claim 9, wherein said
recording head is provided with electro-thermal transducing
elements for generating thermal energy to be used for discharging
ink.
11. A recording apparatus according to claim 10, wherein said
recording head discharges ink from discharge ports by utilization
of film boiling created in the ink by application of the thermal
energy by said electrothermal transducing elements.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a recording apparatus that records
on a recording medium, such as an ink jet recording apparatus and a
thermal transfer recording apparatus. More particularly, the
invention relates to a small recording apparatus which is light in
weight.
2. Related Background Art
As recording methods for a recording apparatus that records on
paper, cloth, plastic sheet, OHP sheet, or the like, there have
been proposed, among others, a wire-dot type, a thermal sensitive
type, a thermal transfer type, and an ink jet recording type, for
example. Such recording apparatus is structured to be able to mount
a recording head on it, to which either one of these recording
types is applicable.
Now, of those recording apparatuses, the description will be made
of the one capable of performing non-impact recording at low noises
by exemplifying a recording apparatus (ink jet recording apparatus)
that records by use of a recording head of ink jet recording type
(ink jet recording head) for recording on a recording medium by
discharging ink from the discharge ports (nozzles) of the head by
the means of recording elements adopted for generating energy to be
utilized for discharging ink.
The ink jet recording apparatus is capable of recording in high
density at high speeds. Also, this type of apparatus can be
fabricated compactly. Its running costs are low, while it is made
easy to record color images by use of multiple color ink. Among
such apparatuses, a line type ink jet recording apparatus that uses
recording means of a line type makes a more enhanced recording
speed possible by use of many numbers of discharge ports arranged
in the width direction of a recording medium.
Because of these advantages, the ink jet recording apparatus is on
the market widely as a printer adopted for the output device of
information processing systems such as a copying machine, facsimile
apparatus, electronic typewriter, word processor, work station, or
utilized as a hand-held or a portable printer provided for a
personal computer, a host computer, an optical disc device, a video
apparatus, or the like.
Although an ink jet recording apparatus is structured in accordance
with the required functions, specifications, and the modes typical
of the system to which such apparatus is applicable, it is
generally practiced that the ink jet recording apparatus is
provided with a recording head, a carriage having an ink tank
mounted on it, feeding means for carrying a recording medium, and
means for controlling them. Then, the recording head provided with
a plurality of discharge ports for discharging ink is used to
serially scan in the direction (main scanning direction)
rectangular to the direction in which a recording medium is carried
(sub-scanning direction), while discharging ink droplets from the
discharge ports in accordance with recording signals. On the other
hand, the recording medium is intermittently fed (pitch fed) for an
amount equal to the recording width during non-recording period. In
this way, the recording is made on the recording medium. At this
juncture, by use of the recording head where a plurality of
discharge ports are arranged on a straight line that extends in the
sub-scanning direction, it is possible to perform a recording
equivalent to the width (recording width) that corresponds to the
number of nozzles (arrangement width of nozzles) just by one
scanning of the recording head on the recording medium.
As the recording elements of an ink jet recording apparatus, that
is, elements for generating thermal energy utilized for discharging
ink, there are, among others, those which use transducing elements
such as piezoelectric elements to effectuate mechanical
transformation when a voltage is applied; those which discharge ink
by the function of heat being generated by the irradiation of
electromagnetic wave such as laser; or those which give heat to
liquid by means of electrothermal transducing elements provided
with heating resistors.
Of the elements described above, the ink jet recording head of a
type that discharges ink by the utilization of thermal energy is
capable of recording in high resolution, because it is possible for
this type of the head to arrange ink discharge ports in high
density. Particularly, the recording head that uses electrothermal
transducing elements as energy generating elements can be
fabricated compactly. Also, when assembling such elements in high
density, it is possible to fully apply the advantages of IC
technology and micro-machining technique whose advancement and
enhancement of reliability are significant in the semiconductor
industry in recent years. The costs of manufacture are also low for
this type of head, among other advantages that it can provide.
Now, there are many apparatuses for which miniaturization has been
intended by making the most of such characteristics as described
above for the recording apparatuses represented by an ink jet
recording apparatus. FIG. 7 is a perspective view which shows one
example of the conventional small recording apparatus. This
recording apparatus 70 is such that a tray 71 is attached thereto
for receiving each medium to be exhausted after recording. On the
front side thereof toward the operator, an operation unit 73 is
arranged with operating switches, indication elements, and others.
The mechanism portion where the recording head and others is
mounted are covered by a lower case 75 and an upper case 76. In
FIG. 7, almost no mechanical portion is shown. In this respect, a
cover 72 is provided for the portion of the upper case 76 where a
carriage is arranged. When recording is performed by use of this
recording apparatus, a separately prepared sheet feeder (not shown)
is coupled to the rear side of the apparatus shown in FIG. 7. The
recording apparatus 70 is arranged so that the operation unit 73
faces upward, and then, the recording medium is supplied from the
sheet feeder one after another (that is, the sheet feeding is
performed in this way). After that, the recording medium is carried
by means of a platen, rollers 74, and others, while a recording
head, such as an ink jet recording head, is being caused to scan
for recording. Thus the recorded medium is exhausted onto the tray
71.
FIG. 8 is a perspective view which shows a state that the cover 72
is removed from the portion where the carriage is arranged. In FIG.
8, the carriage 92 without any recording head being mounted on it,
and a lead screw 79 are observable. The lead screw is provided for
the carriage 92 to travel. Here, a back plate 78 is attached to the
cover 72.
FIG. 9 is a perspective view which shows a state that the upper
case 76 is removed entirely. FIG. 10 is a perspective view which
shows a state that a base board 91 for controller is also removed.
FIG. 9 and FIG. 10 illustrate the base board 91 for controller
where electric circuits are arranged for controlling this recording
apparatus 70, as well as the mechanism unit 93 for operating the
recording medium and carriage 92. The carriage 92 is driven by the
mechanism unit 93 to scan in the directions indicated by arrows in
FIG. 9. On the base board 91 for controller, there are provided the
IC 102 in which the peripheral circuits and other circuits required
for the operation of a CPU 101 are arranged on one chip; switches
103; LEDs 104; a connector 105 for receiving recording signals from
the outside, and the like, in addition to the one-chip CPU (central
processing unit) 101 as the so-called one chip microprocessor.
Also, on the board, the components required for controlling
elements, performing indications, and others are installed. These
components are connected by means of wiring patterns on the board,
respectively. Here, the switches 103 and LEDs 104 are arranged on
the board in the respective positions corresponding to those on the
operation unit 73. This base board 91 for controller is fixed to
the inner face of the lower case 75 by means of screws 95.
In the area where the carriage 92 passes during its traveling
(hereinafter, referred to as a carriage passing area), it is
impossible to arrange any components and members because any
collision should be avoided between the carriage 92 and any one of
them when the carriage scans. In the conventional recording
apparatus 70, the base board 91 for controller, the carriage
passing area, and the mechanism unit 93 are compactly arranged in
parallel on the bottom portion of the recording apparatus unit,
thus having attained making the apparatus smaller to a certain
extent. Here, however, if a continuous recording is required, the
continuous sheet feeding should be arranged for this recording
apparatus. In other words, a separately prepared autosheet feeder
should be coupled to the rear side of the apparatus shown in FIG.
8, that is, the back side of the lower case 75 thereof. Therefore,
the entire size of the apparatus becomes slightly larger than that
of the apparatus shown in FIG. 7 to FIG. 10.
In recent years, there have been more occasions that a recording
apparatus is carried around for use in order to meet the
requirements of the high information society. The demands on an
easily portable recording apparatus are intensified, and it is more
desired to implement the further miniaturization of the recording
apparatus. However, there is automatically a limit to the
miniaturization of the conventionally structured recording
apparaatus such as described above. It is not easy to attain the
miniaturization particularly when the apparatus should be arranged
for a continuous sheet feeding, and the provision of an excellent
portability is a difficult problem to be solved when the further
miniaturization of the apparatus is attempted.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a small
recording apparatus excellent in its portability by attaining the
further miniaturization of a recording apparatus.
It is another object of the invention to provide a recording
apparatus comprising a carriage that enables a recording head for
recording on a recording medium to relatively travel with respect
to the recording medium; a mechanism unit for driving the carriage
and carrying the recording medium at the same time; and a
power-supply circuit, wherein the power-supply circuit can be
formed on a printed circuit board by forming a slanting portion for
the mechanism unit as a passage to carry the recording medium, and
then, in a space made available below the slanting portion, the
components that constitute the power-supply circuit are arranged
substantially in line in the direction substantially rectangular to
the direction of the slanting portion.
It is still another object of the invention to provide a recording
apparatus comprising a carriage that enables a recording head for
recording on a recording medium to travel relatively with respect
to the recording medium; a mechanism unit for driving the carriage
and carrying the recording medium at the same time; a base board
for controller including a power-supply circuit; and the components
constituting the power-supply circuit being arranged on one face of
the base board for controller, and being connected to each other by
means of wiring pattern at the same time, wherein the mechanism
unit is provided with a slanting portion as a passage to carry the
recording medium, at least a part of the base board for controller
is arranged in the space available below the slanting portion, the
components constituting the power-supply circuit are arranged
substantially in line in the direction facing such space and also
substantially rectangular to the slanting portion, and the width of
the wiring pattern between the components constituting the
power-supply circuit is defined at the rate of 700 .mu.m or more
per current of 1 A passing the wiring pattern.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the way in which the mechanism
unit and base board for controller are installed on the lower case
of an ink jet recording apparatus in accordance with one embodiment
of the present invention.
FIG. 2 is a plan view which shows a base board for controller.
FIG. 3 is a perspective view which shows an ink jet recording
apparatus in accordance with one embodiment of the present
invention, and which illustrates a state where its housing is
removed.
FIG. 4 is a perspective view which shows the ink jet recording
apparatus represented in FIG. 3, and illustrates a state where its
housing is installed.
FIG. 5 is a cross-sectional view which shows the structure of
principal part of the ink jet recording apparatus represented in
FIG. 3.
FIG. 6 is a perspective view which illustrates a panel board.
FIG. 7 is a perspective view which shows the external appearance of
one example of the conventional recording apparatus.
FIG. 8 is a perspective view which shows a state where the cover of
the apparatus represented in FIG. 7 is removed.
FIG. 9 is a perspective view which shows a state where the upper
case of the apparatus represented in FIG. 7 is removed.
FIG. 10 is a perspective view which shows a state where the base
board for controller of the apparatus represented in FIG. 7 is
removed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, with reference to the accompanying drawings, the description
will be made of the embodiment in accordance with the present
invention. Here, as the example of a recording apparatus, an ink
jet recording apparatus will be described. FIG. 1 is a view showing
the way in which the mechanism unit and base board for controller
are installed on the lower case of an ink jet recording apparatus
in accordance with one embodiment of the present invention. FIG. 2
is a plan view which shows the base board for controller. FIG. 3 is
a view which shows the ink jet recording apparatus represented in
FIG. 3, and which illustrates a state where its housing is removed.
FIG. 4 is a view which shows the ink jet recording apparatus
represented in FIG. 3, and which illustrates a state that the
housing is installed.
A recording apparatus of the kind is provided with a slanting
portion for its mechanism unit as a passage to carry a recording
medium, and then, a base board for controller is arranged in a
space made available below the slanting portion. Therefore, it is
possible to utilize the space three-dimensionally for the
attainment of the miniaturization of the recording apparatus. Here,
the components constituting a power-supply circuit (power-supply
circuit components) are generally tall. Therefore, the power-supply
circuit components are arranged substantially in line facing the
space, and also, in the direction substantially rectangular to the
direction of the slanting portion provided as a passage to carry
the recording medium. In this way, it is possible to enhance the
efficiency of the space utilization for the attainment of the
further miniaturization of the recording apparatus.
Also, for the present embodiment, it is possible to use an ink jet
recording head as the recording head that discharges ink in
accordance with signals. In this case, the recording head can be
provided with electrothermal transducing elements to generate
thermal energy to be utilized for discharging ink. The recording
head can discharge ink from the discharge ports by the utilization
of film boiling created in ink by the application of the thermal
energy generated by the electrothermal transducing elements.
Also, as another mode of the ink jet recording head, it may be
possible to provide electro-mechanical transducing elements such as
piezo-elements, and then, discharge ink from the discharge ports by
utilizing the mode transformation effectuated by use of the
electro-mechanical transducing elements.
For the ink jet recording apparatus of the present embodiment, the
base board 51 for controller to which a shielding board 52 is fixed
by means of small screws is arranged to be overlapped with the
mechanism unit 53 that carries the recording medium and drives the
carriage as shown in FIG. 1. Further, as shown in FIG. 2, the
arrangement of each circuit component of the base board 51 for
controller is devised so as to attain the further miniaturization
of the apparatus. Now, at first, in conjunction with FIG. 3, the
ink jet recording apparatus will be described in accordance with
the present embodiment. In FIG. 3, a carriage 2 is arranged to
detachably mount a recording head cartridge 1, and slidably
supported by the guide shaft 5 and guide rail 12 fixed to a frame 4
at both ends thereof so as to be arranged in parallel to each
other, and also, slidably supported in the direction rectangular to
the feeding direction of a recording medium P and in the direction
parallel to the plane of the recording medium P as well. Also, the
carriage 2 is coupled to one location of a carriage driving belt 11
tensioned around the driving pulley 13 fixed to the output shaft of
a carriage driving motor 10 and a rotatively and axially supported
free pulley (not shown). With this structure, therefore, the
carriage driving belt 11 rotates to allow the carriage 2 to
reciprocate in the direction described above when the carriage
driving motor 10 is driven.
The recording head cartridge 1 is integrally formed by the
recording head unit that discharges ink in accordance with
recording signals, and an ink tank 30 that retains ink in it. The
cartridge is detachably mountable on the carriage 2. The ink tank
30 may be an exchangeable ink tank that can be attached to or
detached from the recording head unit. The recording head unit
utilizes the thermal energy generated by electrothermal transducing
elements as energy to be used for recording, and discharges ink
downward in FIG. 3, thus executing recording on a recording medium
P. The recording signals are transmitted from the base board 51 for
controller (which will be described later) to the recording head
unit through a flexible cable 3 connected to the carriage 2. The
flexible cable 3 is arranged in the traveling direction of the
carriage 2. Along the traveling of the carriage 2, the cable forms
a loop.
FIG. 4 is a view which shows a state where the ink jet recording
apparatus represented in FIG. 3 is housed. The housing, that is,
the exterior thereof, comprises a lower case 18 and an upper case
17. In the interior of the housing thus arranged, the main body
portion of the ink jet recording apparatus described above is
installed.
On the depth side of the upper case 17, a top cover 19 is arranged
to be freely opened or closed for covering the upper case 17. The
upper case 17 is provided with an aperture in a location
corresponding to a pressure board 8. When the top cover 19 is
opened, the top cover 19 becomes a tray that serves to set the
recording medium P on the pressure board 8. Further, the upper case
17 is provided with an aperture beginning at its central portion to
the front part. Through this aperture, the recording head cartridge
1 or the ink tank 30 can be attached or detached. Therefore, when a
replacement should be made for recording head cartridges 1 or ink
tanks 30, the carriage is driven to travel to the central portion
of its traveling range by means of a given operation. On the front
side of this aperture for use of the replacement of recording head
cartridges 1 or ink tanks 30, a head cover 20 is arranged to be
freely opened or closed to cover a part of the upper face of the
aperture and the front end thereof. The head cover 20 is closed if
there is no replacement needed for recording head cartridges 1 or
ink tanks 30, thus protecting the recording head cartridge 1
currently in use.
Here, the recording medium P is stacked on the pressure board 8,
both ends of which are rotatively supported on the frame 4. The
pressure board 8 is biased by a biasing means (not shown) to a
pickup roller 9. The recording medium P stacked on the pressure
board 8 is pressed to the pickup roller 9. In accordance with a
sheet feed command, the pickup roller 9 rotates. Then, by the
application of frictional force between the pickup roller 9 and
recording medium P, the recording medium P is fed out. Here, the
pressure board 8 is provided with separation means (not shown)
formed by a separation nail and others such as used for the
conventional automatic sheet feeding device. Therefore, even when
plural sheets of recording medium P are stacked on the pressure
board, only one recording medium P laid on the top of the stack is
fed out by the function of this separation means. In other words,
with this setup, an automatic sheet feeding function is
realized.
The recording medium P fed out by means of the pickup roller 9 is
carried downward to a position below the carriage 2, while being
pinched by the feed roller 6 whose ends are supported on the frame
4, and a pinch roller 7 installed on the base 14. In this position,
recording is made on the recording medium P. Further, on the
downstream side of the carriage 2 in the feeding direction of the
recording medium P, a sheet exhaust roller (exhausting roller) 15
and a spur 16 are arranged to face each other. The recording medium
P having passed below the carriage 2 is pinched by the sheet
exhaust roller 15 and spur 16 to be exhausted. The pickup roller 9,
feed roller 6, and sheet exhaust roller 15 are driven by a sheet
feed (feeding) motor (not shown) as the power source of these
rollers.
Here, in the description given below, the upstream side (sheet
feeding side) of the recording medium P is defined as depth side,
and the end face thereof is defined as back face, while the
downstream side (sheet exhausting side) is defined as front side,
and the end face thereof is defined as front face. Hence, the
recording medium P is being carried from the depth side of the ink
jet recording apparatus to the front side thereof.
In accordance with the recording apparatus of the present
embodiment, the structural portion on the depth side is in the
slanting direction with respect to the bottom face of the apparatus
that serves as reference. More specifically, the pressure board 8
is arranged so that the depth side is raised, while the front side
is lowered, thus making it possible to arrange the base board 51
for controller in a space thus made available below the pressure
board 8. At the same time, it is made possible to materialize the
automatic sheet feeding function (autosheet feeder function) as
described above in such small space.
Now, in conjunction with FIG. 1, the description will be made of
the arrangement of the mechanism unit 53 and base board 51 for
controller for this ink jet recording apparatus. FIG. 1 is a
perspective view of the apparatus drawn as being observed from its
back face side. The mechanism unit 53 and base board 51 for
controller should be electrically connected. This electrical
connection is made by use of a flat cable 3 and cables 55 and 56.
Also, as described later, the operational switches, indication
LEDs, and others are installed on the panel board, but this panel
board, and base board 51 for controller are connected by use of a
card type cable 54 that has been processed in a given
configuration.
With the sheet feeding mechanism structured as described above, the
base board 51 for controller is arranged below the pressure board 8
formed in the slanting direction. In other words, the base board 51
for controller coupled with the shield board 52 is incorporated on
the depth side (in the front direction in FIG. 1) of the lower case
18. Then, the structure is arranged to incorporate the mechanism
unit 53 that comprises the pressure board 8 whose back face is
slightly pushed out; the carriage 2; the frame 4; and others on the
front side of the lower case 18 (in the depth direction in FIG. 1).
After all, the structure is formed in such a manner as to
three-dimensionally arrange the portion related to sheet feeding
including the pressure board 8 on the back face of the mechanism
unit 53, and the base board 51 for controller, that is, a part of
the mechanism unit 53 and base board 51 for controller. In this
way, the further miniaturization of the recording apparatus can be
implemented.
Now, in conjunction with FIG. 2, the description will be made of
the arrangement of components on the base board 51 for controller.
Generally, a recording apparatus of the kind is provided with a
power-supply circuit incorporated in it. For the recording
apparatus of the present embodiment, too, a power-supply circuit is
formed on the base board 51 for controller. In other words, on the
base board 51 for controller, which is formed as a printed circuit
board, there are arranged a power-supply connector 201 serving as
the insertion port for the power-supply; various components of the
power-supply circuit designated by numerical references 202 to 212;
a connector 213 for interface use in order to receive recording
signals from the external device; connectors 214 and 215 for
connecting cables to the carriage driving motor and recording
medium feeding motor; a connector 216 for coupling the flat cable
terminal connected to the recording head unit; a CPU chip 217; a
controlling memory 218; and a memory 219 for provisional storage.
In the components of the power-supply circuit, large electrolyte
capacitors 204 and 208, a troidal coil 205, a filter 203 or
switching elements 206 and 207, and others are included. The
controlling memory 218 is a ROM (read only memory) storing control
program and others for use of the CPU chip 217, for example. The
memory 219 for provisional storage is a DRAM (dynamic random access
memory), for example.
In accordance with the present embodiment, the CPU chip 217 is
arranged substantially in the center of the base board 51 for
controller. The CPU chip 217 is provided with a central processing
unit (CPU) and a considerable portion of required circuits in the
form of one chip. With this one-chip formation, the area occupied
by them on the base board becomes smaller significantly, hence
largely contributing to the intended miniaturization. The CPU chip
217 is thin and formed substantially in square, which is typically
formed by means of QFP (quad flat package). On each side thereof,
many leads are arranged, respectively. The assignment of the leads
to the CPU chip 217 is made so that each of the leads is orientated
in the direction to the other elements to which each of the leads
is related. For example, the leads related to the controlling
memory 218 are arranged on the side A of the CPU chip 217 in FIG. 2
so as to orientate them toward the controlling memory 218.
Likewise, the leads related to the memory 219 for provisional
storage are arranged on the side C so that these leads are
orientated toward the memory 219 for provisional storage. With the
controlling memory 218 and the memory 219 for provisional storage
being a ROM and a DRAM, respectively, it is necessary to install
many wires for use of address/data buses between the CPU chip 217,
controlling memory 218, and memory 219 for provisional storage.
Therefore, unless care is given particularly to the arrangement of
these wires, its drawing tends to become redundant, resulting in
the scattered wiring patterns on the base board, and making it
impossible to implement the intended miniaturization of the base
board 51 for controller.
In accordance with the present embodiment, the controlling memory
218 and the memory 219 for provisional storage are arranged close
to the sides A and C of the CPU chip 217, respectively, as shown in
FIG. 2, for example. Further, among the leads on the CPU chip 217,
those to be connected with the controlling memory 218 and the
memory 219 for provisional storage are put together and arranged on
the A side and C side, respectively. As a result, any redundant
drawing of wiring patterns, such as being drawn from the C side to
A side of the CPU chip 217, can be avoided, and the resultant
length of wires can be shortened between the CPU and the
controlling memory 218 and the memory 219 for provisional storage.
In other words, the leads needed for a series of signals
transmitted to one and the same external element are put together
on the CPU chip, and then, structured so as to orientate them
toward such external element. In this way, any redundant drawing of
wiring patterns is prevented, thus producing favorable effects on
miniaturizing the base board, particularly when making the width of
its shorter side smaller.
Also, for the base board 51 for controller, the structure is made
to arrange comparatively tall components, such as large electrolyte
capacitors 204 and 205, troidal coil 205 and others, on the depth
side (sheet feeding side) of the recording apparatus, while
arranging those components whose height is lower on the front side
(sheet exhausting side) of the recording apparatus. The components
of the power-supply circuit and connectors for external use are
generally large. Therefore, with respect to the connector 201 for
power-supply use, electrolyte capacitors 204 and 208, troidal coil
205, filter 203, switching elements 206 and 207 or connector 213
for interface use, for example, there is no alternative but to use
tall components. Here, as described earlier, the pressure board 8
is slantly arranged for sheet feeding above the base board 51 for
controller, hence making it impossible to arrange the tall
components on the front side of the recording apparatus. For the
base board 51 for controller, therefore, it is structured to
arrange the power-supply circuit on the left side toward the depth
side of the recording apparatus, and then, arrange the connector
201 for power-supply use and electrolyte capacitors 204 and 208
accordingly, while arranging the interface circuit on the right
side so as to provide the connector 213 for interface use on that
side. In other words, the tall components are arranged on the
portion where there is more distance to the pressure board 8 (that
is, the portion having more clearance).
According to the conventional practice, it is necessary for a
power-supply circuit to make the connecting wire/wiring pattern
between components on the printed circuit board as short as
possible, because the current running across the components is
great. To satisfy this condition, the area for arranging the
components of the power-supply circuit should be made as small as
possible: for that matter, these components are usualy arranged on
a circular or square area. In contrast to it, the base board 51 for
controller of the present embodiment allows the components of the
power-supply circuit to be arranged substantially in line along the
longer side of the base board 51 for controller, thus effectively
utilizing the space available in the recording apparatus for the
attainment of the miniaturization of the recording apparatus. In
this respect, however, it becomes particularly important to give
serious consideration to the width of wiring patterns between the
components as described below, because the components of the
power-supply circuit are to be arranged substantially in line.
In general, a printed circuit board of the kind is structured by
assembling components on the printed circuit board on which wiring
patterns are formed. A wiring pattern is usually formed by
patterning a copper foil of 18 .mu.m thick in a desired
configuration. As it can be assumed that the thickness of the
wiring pattern and volume conductivity are constant, the electric
resistance of the wiring pattern is determined by the width and
length of the wiring pattern. Particularly, the electric resistance
depends largely on the width of the wiring pattern. In order to
operate a recording apparatus of the kind normally, while
suppressing the heat generation of the wiring pattern, the electric
resistance of the wiring pattern should be kept at values less than
a specific level. As a practical problem, it is necessary to
determine the width of the wiring pattern at a rate of 700 .mu.m or
more per running current of 1 A (ampere) between the components of
the power-supply circuit whose running current is large. In
accordance with the present embodiment, a current of maximum 3 A
may be caused to flow. Therefore, the width of the wiring patterns
of the power-supply circuit is made to be 3.1 mm or more even for
the narrowest area where the patterns are arranged. Also, the
components of the power-supply circuit should be arranged in line.
Therefore, the length of the wiring patterns tends to be longer.
The resistance becomes larger in proportion to the length, and the
voltage drop becomes greater. It is, therefore, preferable to
define the wiring width at the rate of 850 .mu.m or more per ampere
if the length of the wiring pattern (connection) becomes greater.
Also, in consideration of influences exerted by temperatures, the
formation of patterns, and others, it is more preferable to make
the wiring width to be 1 mm or more per charged current of 1 A in
order to secure more reliable operation.
With the structure described above, it is possible to arrange the
base board 51 for controller below the pressure board 8 formed in
the slanting direction: in other words, a part of the mechanism
unit and the base board for controller can be arranged
three-dimensionally in part, thus remarkably contributing to making
the ink jet recording apparatus smaller. Also, for the reasons
described above, the position of the interface connector 213, and
the positions of the series of components of the power-supply
circuit are determined by the arrangement configuration on the
depth side of the recording apparatus. For example, the
power-supply circuit is arranged on the left-hand side, while the
interface circuit and interface connector 213 on the right-hand
side as described earlier. To these circuits and components,
signals are supplied from the CPU chip 217, and the lead lines of
the CPU chip 217 are connected therewith. The lead lines related to
these connections are arranged together on the CPU chip 217 side,
and orientated toward these circuits and components. In other
words, the lead lines related to the interface connector 213 of
those lines of the CPU chip 217 are arranged on the right half of
the side D thereof as shown in FIG. 2 so as to connect them with
the interface connector 213 in a comparatively short distance.
Also, the relationship between the CPU chip 217 and other circuit
elements are the same as described earlier. With such arrangement
mode, it is possible to prevent patterns from being drawn around
wastefully, hence making the base board smaller, and in turn,
attaining the miniaturization of the apparatus as a whole.
FIG. 5 is a cross-sectional view of the ink jet recording apparatus
observed from the frame 4 side (see FIG. 1). In FIG. 5, only the
pressure board 8, the pickup roller 9, and base 14 are represented
for the mechanism unit 53 in order to show the positional
relationship clearer. Also, on the lower case 18, an opening of the
power-supply connector 201, that is, the power-supply inlet port
201a, is provided. The base board 51 for controller is housed in
the location of a flat portion 509 in the inner face of the lower
case 18. More specifically, as shown in FIG. 5, a step 510 is
arranged on the lower portion of the pressure board in the slanting
direction in order to incorporate the base board in the lower case
18 of the recording apparatus unit without using any screws or
other fixing means, but in the mode of being fixed by pressure
exerted by means of the step 510 thus arranged and a nail 357
provided in the depth side of the lower case 18. Here, the bosses
355, 356, and 357 are integrally formed by resin formation together
with the lower case 18. The bosses 355, 356, and 357 are also
elastic. As a result, the base board 51 for controller is also
fixed by the application of the elasticity of these bosses 355,
356, and 357.
With the arrangement of this structure, there is no need for the
provision of screws and the bosses prepared for use of the screws,
thus making it easier to assemble the base board for controller,
while this structural arrangement contributes to saving space and
to attaining the miniaturization of the apparatus eventually.
Now, in conjunction with FIG. 6, the description will be made of
the panel board on which are arranged switches and indication unit
needed to operate the ink jet recording apparatus. On the panel
board 601, switches 602 to 607, indication LED 608, indication
panel 609, and buzzer 611 are installed. The structure is arranged
to let the operator input his instructions, while indicating to or
informing him of the information required by him. Further, on this
panel board 601, are arranged a sheet absence sensor 610 that
detects the presence and absence of a recording medium; a home
position sensor 614 that detects whether or not the carriage 2 is
in the home position; and a connector 615 for coupling the card
type cable to the base board for controller. This panel board 601
is installed on the mechanism unit 53 by means of fixing screws 612
and 613.
This structure differs from that of the conventional recording
apparatus in that such switches and indication members are arranged
in the gap between the pressure board for carrying the recording
medium, and the traveling area of the carriage, and then, the
switches and indication members are installed on the panel board
601 serving as a child board, which is connected by a card type
cable 54 (see FIG. 1) to the base board 51 for controller, a
parents board, where CPU chips and others are installed. The
location where the panel board 601 is arranged is in the recess on
the mechanism unit 53. Here, by installing the panel board in such
a manner, it is possible to implement another space saving.
In this respect, the description has been made of the present
invention in accordance with the embodiment described above,
wherein a printer is provided with a carriage having an ink jet
recording head mounted thereon. However, with the arrangement of a
scanner unit whose outer appearance is substantially the same as
that of the ink jet recording head, it is possible to mount such
scanner unit on the carriage compatibly with the ink jet recording
head, hence allowing the apparatus to function as an information
processing apparatus capable of reading image information from a
source document supported by the platen of the apparatus. Even in
such case, too, the structure described for the present invention
is preferably applicable.
Further, the description has been made of the present invention by
exemplifying an ink jet recording apparatus as its embodiment, but
the present invention is not necessarily limited to the ink jet
recording apparatus. It is also applicable to various other
recording apparatuses of a thermal sensitive type, thermal transfer
type or the like.
Moreover, as modes of recording apparatuses of the present
invention, it may be possible to adopt a copying apparatus arranged
in combination with a reader, and a facsimile apparatus provided
with transmission and reception functions, in addition to such
modes in which the recording apparatus is used individually or
integrally as an image output terminal of a word processor,
computer, or other information processing apparatus.
As described above, the embodiment of the present invention is such
that a slanting portion is provided for the mechanism unit as a
passage for carrying a recording medium, and then, a base board for
controller is arranged in the space below this slanting portion. In
this way, it is possible to utilize the space three-dimensionally
and attain the miniaturization of a recording apparatus
effectively. Also, facing such space, and in the direction
substantially rectangular or transverse to the slanting portion
that serves as the passage for carrying the recording medium, the
components of the power-supply circuit are arranged substantially
in line, thus enhancing the efficiency of space utilization for the
attainment of the further miniaturization of the recording
apparatus. Moreover, the width of wiring patterns between the
components of the power supply circuit is defined at a given rate
in accordance with the current passing the wiring patterns, hence
making it possible to prevent any influence from being exerted by
the voltage drop down.
* * * * *